I've disabled all mods except for the Vehicle Mod and Obfuscate, and even removed all of my resource packs, BUT, I'm not able to use any of the items, like the workstation, etc. If I try to place a workstation down, it immediately disappears. The mod itself loads fine, all the items are there (wheels, engines, crates, etc) but I just can't get going. What am I doing wrong? Am I missing something?

Are you playing singleplayer or on a server? If you're playing on a server, you must have the mod installed on the server too. It can just be a vanilla server. From what I recall, you can still access the items in creative but placing them down won't work and that sounds exactly like your issue. I'm going to close this because it's definitely a problem with what you're doing and nothing to do with my mod.

I’m playing on creative, on Realms, on my laptop. You could have given me more of your time, instead of just shutting me down. Thanks for nothing.

I'm not shutting you down. I know how mods work and they won't run on a vanilla/realms server. I'm no longer going to help you because apparently me telling you the problem isn't enough. Good luck!